5:15 PM - 6:45 PM
[ACG45-P01] Aircraft observations of aerosols and clouds during High Ice Water Content (HIWC) flight campaigns in 2022: CCN and INP abilities of aerosol particles
Keywords:High ice water content, Aerosol-cloud interactions, Ice nucleating particle, Cloud condensation nuclei
In order to investigate the formation and development mechanism of high ice water content (HIWC) in deep convective clouds, and elucidate how the abundance of aerosol particles acting as CCN/INP may influence the HIWC conditions, we conducted two flight campaigns in 2022 using NASA’s DC-8 research aircraft: HIWC-2022 in Florida, USA in July and CPEX-CV in Cabo Verde in September. In-situ microphysical properties of aerosol particles as well as of hydrometeors from the convective clouds were obtained.
The aerosols were sampled at different altitudes and locations, with each particle analyzed by electron microscopy that enabled us to classify into several types of aerosols. From the backward trajectory analysis, the origins of sampled air mass were mostly over the ocean for HIWC-2022 whereas those were mostly over the land for CPEX-CV.
The CCN number concentrations were found to be well-correlated with aerosol loading for HIWC-2022, but not so correlated for CPEX-CV due to stably low CCN concentrations. A hygroscopicity parameter of aerosols was one order lower for CPEX-CV, although even the values for HIWC-2022 were lower than typical continental cases. The INP number concentrations in both campaigns were similar and comparable to previous studies or higher in some cases at temperature ranges between -25C and -5C. A parameter of ice nucleation active surface site (INAS) density at temperatures colder than -20C in both campaigns may be explained through the mineral dust parameterizations from previous studies.
The aerosols were sampled at different altitudes and locations, with each particle analyzed by electron microscopy that enabled us to classify into several types of aerosols. From the backward trajectory analysis, the origins of sampled air mass were mostly over the ocean for HIWC-2022 whereas those were mostly over the land for CPEX-CV.
The CCN number concentrations were found to be well-correlated with aerosol loading for HIWC-2022, but not so correlated for CPEX-CV due to stably low CCN concentrations. A hygroscopicity parameter of aerosols was one order lower for CPEX-CV, although even the values for HIWC-2022 were lower than typical continental cases. The INP number concentrations in both campaigns were similar and comparable to previous studies or higher in some cases at temperature ranges between -25C and -5C. A parameter of ice nucleation active surface site (INAS) density at temperatures colder than -20C in both campaigns may be explained through the mineral dust parameterizations from previous studies.